A typo and a link update in latex-utils document.

[encomer]

About the typo:
At the end of section 2 in the latex-utils document with link:
https://docs.racket-lang.org/utils/index.html#%28mod-path._latex-utils%2Fscribble%2Fmath%29
it says:
Uses style-matrix with all left-aligned colunms.
should say:
Uses style-matrix with all left-aligned columns.

About the link to update:
At the beginning of section 7 it reads:
Jesse Tov has an excellent LaTeX package for typesetting rigorous proofs..
The new link is: https://users.cs.northwestern.edu/~jesse/code/latex/.

Thank you.